Diaphragm core blowing apparatus



Nov. 21, 1944. F. PFEIFFER DIAPHRAGM CORE BLOWING APPARA'I US Filed Dec. 17, 1941 III /6 zngv,

Patented Nov. 21, 1944 v DIAPHRAGM CORE BLOWING APPARATUS Albert F. Pfeifier, West Allis, Wis.,.assignor to Allis-Chalmers Manufacturing Company, Milwaukee, Wis., a corporationof Delaware Application December 17, 1941,'Serial No. 423,311

12 Claims.

This invention relates generally to core blowing and more particularly to apparatus for blowing relatively long and narrow cores, such for example as the blade holding core segments used in molds forcasting turbine wheels, diap-hragms and the like. In casting turbine diaphragms, the blade holding core usually comprises asand ring segment embodying a series of spaced curved blades extending transversely therethrough and presenting inner and outer free end portions adapted to have the inner and outer diaphragm disk portions cast integrally thereto. Prior to this invention, such cores were formed by positioning the blades in predetermined angularrelation in a suitable core box including means for preventing the core forming material, hereinafter referred to as sand, from entering the spaces defined by the free end portions of the blades and then hand ramming thebox with sand to form the blade holding core. When the blades are positioned in the core box, the intermediate concave and convex portions of adjacent blades coact and form therebetween relatively narrow curved passages which render hand ramming extremely difficult. For example,

about one hour and twenty minutes is required to hand ram a forty-two inch diameter, one hundred eighty degree blade holding core segment. Moreover, in many instances hand ramming has failed to pack the sand sufl'lciently to prevent the molten metal entering the mold from Washing away a portion of the core, which is termed a core washout, and which frequently produces a defective casting. Consequently, hand rammed cores are expensive and in numerous instances .result in defective castings, thereby materially increasing the cost of the finished article.

' blowing head;

I It is therefore the primary object of this invention to provide an improved core ramming or blowingapparatus which is operative to uniform ly pack the sand in the spaces between the blades or other elements disposed in spaced relation within the core box in only 'a small fraction of the time required for hand ramming same.

Another object of this invention is to provide an improved portable core blowing apparatus which isreadily applicable to core boxes of different width and which is operative to uniformly pack the sand in the spaces between the blades or other elements disposed in spaced relation within a relatively long and narrow core. box simply by effecting a relative movement of said apparatus and box. I

Still another object of this invention is to provide an improved core blowing apparatus includinga portable nozzle head which'is adapted to be A further object of this invention is to provide an improved core blowing apparatus comprising a portable nozzle head which is adapted to be mounted on an elongated core box so as to permit relative movement of the box and head and which includes a sand confining member operatively associated with the discharge end of the nozzle and with the interior of the core box so as to form, when-said relative movement is effected, a progressively moving compartment into which the discharge end of the nozzle projects.

The invention accordingly consists of the various'features of construction, combinations of elements,'and arrangements of parts as is more fully set forth in the appended claims and in the detailed description in which:

Fig. 1 illustrates [the invention applied to a core box for forming the blade holding cores used in'casting' turbine diaphragm segments;

- Fig. 2 is a partial plan View of the core box and blowing head shown in Fig. 1;

Fig. 3 is a 'partialsection taken on line ILL-III of Fig. 1; t

) Fig. 4 is a view taken on line IV-IV of Fig. 1; Fig. 5 is an end view of the blowing machine hose connector;

Fig. 6 .is a plan view of the underside of the Fig. 7 is a plan view illustrating the invention applied to straight core box;

Fig. 8 is a section taken on line VIII-VIII of Fig. 7; and

Fig. 9 is a section taken on line IX-4X of Fig.

Referring to the drawing and particularly Figs, 1 and 2, it is seen that the 180 segment core box to which the invention is applied comprises "a base portion I and inner and outer drag ring portions 2 and 3, respectively. The base portion includes inner and outer bottom members 4 and 6, respectively, between which is disposed a lower blade holding jig I and a series of inner and outer filler blocks 8 and 9, respectively, are disposed between the end portions ot the blades l I held in the jig 1. The filler blocks are clamped in position by means of inner and outer clamping member I2 .and' I3, respectively, and the blades I I are also clamped in the jig I by means of an upper blade engaging jig I4. The top surface of the outer drag ring segment 3 is provided with a face plate I6 which extends beyond the outer edge of the drag ring 3 and which coacts with the top of the .clamping segment I3 and. forms therewith a substantially flat surface which 'lies in substantially the same plane as does the substantially flat top surfacepresented by the inner drag ring 2 and the inner clamping member I2. The free ends of the core box are provided with cover plates l1, only one of which is" showriinthe interest of simplicity, and the jig rings 1 and M extend through the plates H in the manner shown in Figs. 1 and 2. A cross member l8 con,- nects and. braces opposite end portions of the inner drag ring 2 as is best shown Fig. 2. The detailed construction of the illustrated core box andthe manner in which the blades and the filler blocks are disposed and held therein is fully disclosed and claimedv in my copending application S; N; 420,263; filed November 24, 1941,-and a more detailed description of the core boxv is deemed unnecessary for a complete understanding of this invention.

Removably attached to the top of the core box is a portable core blowing head l9 comprising .a base member 2| having therein a pair of radially extending. and radially spaced slots 22 and 23, a pair of nozzle carrying members 24 and 26, and a stub shaft carrying member 21. The nozzle carrying members 24 and 26 are mounted on the top surface of the base member 2| for relative radial movement by means of the slot and cap screw connections designated 28, 29 and 3|, 32', respectively. The stub shaft carrying member 21 is also mounted on the base member 2| for relative radial movement by means of the radially spaced slot and, cap screw connections designated 33 ,andv 34. Member 21 carries a stub shaft 36- which has its externally threaded lower end portion screwed into the internally threaded centering socket 3! provided in the cross member. |8. Member 21 is rotatably mounted on the stub shaft 31; andconsequently, when the member 21 is secured to the base member 2| and the stub shaft 33 is fixed in the centering socket 31 as shown in Figs. 1 and 2,. the base member 2| and the. members 24and 26 mounted thereon are rotatable as a unit about the stub shaft 36. In other words, the core blowing head is coaxially and with the sides of the box and jig ring and form therewith a compartment into which the nozzles 38 project. Consequently, it should be obvious that sand discharged through the nozzles 38 will be substantially confined within said compartment, that the air entering the compartment together with the sand and the air displaced therein is free to escape through the spaces provided between the edges of the members 4| and the inlet edges of the blades H and the sides of the box and jig ring l4, and that a relative movement of the box and head produces in effect a movement of the head along the boxand the progressive formation of a compartment into" which the sand is delivered from the nozzles 38'. In this connection, it is prefer-" able, although not necessary, that the relative movement is such as to produce in effect a movement of the head in the direction indicated by the arrow in Fig. 3.

The outer edge of the base member 2| is preferably provided with a depending arcuate flange 42 which carries rollers 43 adapted to engage the exposed underside of the face plate It on the drag ring segment 3 as is clearly shown in Figs. 1 and 2. The upper surface of the base member 2| is provided with a pair of spaced, upwardly extending handles 44 which are adapted to be grasped by the operator in effecting a movement of the head along the box to progressively blow same. The bottom surface of the head, i. e., the member 2|, is provided with rollers 45, 4'! and 48 adapted to engage the top surface of the core box and the jig ring M in order to facilitate a relative movement of the box and head. In this connection, it is preferable that the box be held stationary and that the head be moved along j'ournaled with respect to the arcuate shaped core forming portion of the core box. The members 24 and 26 each carry a nozzle 38, and the nozzles 38 extend through the underlying slot 23 in the base member 2| and into the space provided between the sides of the upper jig ring M and the opposed side surfaces of the drag ring segments 2 and 3 as is clearly shown in Fig. 1. When the width of the core box and jig ring M are such that the members 24 and 26 are radially spaced apart, the space between these members is preferably closed in any suitable manner, such for example, as by means of a plate 39 which is screwed to the base member 2| as shown in Figs. 1 and '2. The discharge end of each nozzle 38 carries asand confining member 4| having a radial width which is slightly less than the radial distance between the sides of the upper jig ring l4 and the opposed sides of the drag rings 2 and 3. The ends of the members 4| project into the core box beyond the discharge ends of the nozzles 38 and are arranged to coact with the u per or inlet edges of a plurality of blades II as shown in Fig. 3 so as to coact with said edges the air chamber 53 as is 'shown in Fig. 1.

the top of the box by the operator grasping the handles 44. Movement of the head relative to the box is permitted by the roller engaging construction previously described and by means of the movable or flexible conduits 49 connecting the nozzles 38 with the sand blower 5|.

Sand blower 5| comprises a stationary frame 52 onwhich is mounted. a stationary air chamber 53 having a discharge opening 54 which is provided with a diffuser 56, a stationary sand hopper 51. having a discharge opening 58, a movable 'open top sand receptacle 59 which is adapted to be alternately positioned in alinement with the discharge opening 54 in the air chamber 53 and the discharge opening 58in the hopper El, and a vertically movable table 6| which is adapted to engage the ends of the downwardly extending projections 62 on the sand receptacle 59 and move same into firm engagement with the bottom of The upper portion of receptacle 5!! is provided with a laterally extending closure member 63 which covers the discharge opening 58' in the hopper 5! whenever the receptacle is positioned beneath the air chamber 53 as shown. Movement of the receptacle 59 from the position shown to its posi tion beneath the hopper 5! is efiected by first movingfla conventional two-way valve 64 so as to close the branch air line 66 and place the space beneath underside of the table piston 61 in communication with the atmosphere through the vent pipe 68, and by then moving the conventional two-way valve 69' so as to close the air line branch pipe. 11' and place the interior of cylinder 12 in communication with the atmosphere through the vent pipe 13; When valve 64 is moved as stated, the sand receptacle 59 moves downward until the rollers 14 carried thereby engage the track 16 and the stated movement of valve 69 permits spring 11 to retract the receptacle 59 and. the connected piston 18 which is disposed in the cylinder 12, to the right untilthe upper open end of the receptacle is positioned in alinement with the opening 58 in the hopper 51.

When the receptacle is thus positioned, sand flows a conduits 49, nozzles 38 and into the core box is to open the normally closed valve 19 by means of a suitable operator, such as handle 8|, which admits air under pressurefrom the main air line 82, which is connected with'a suitable source of air under pressure (not shown), into the chamber 53 from which it passes through the opening 54 into :the receptacle 59 and forces the sand out through the nipples I and the conduits 49 ,connected thereto. The sand blower herein shown and described is merely illustrative of a practical means for forcing the. sand through the conduits 49 and nozzles 38 and ittherefore should be understood that it is not desired to limit the invention to any particular type of sand blower as any suitable sand blower may be employed. In this connection, it should also beunderstood that it is not desired to limit the invention to core boxes embodying curved or arcuate shaped core forming portions, as the invention is readily applicable to relatively long and narrow straight core boxes as is obvious from a consideration of Figs. 7, 8 and 9 which shows theinvention applied to a substantially straight core box and in which like numerals are used to designate the same or similar parts.

In this applicatiom the core box differs from that. shown in Figs l, 2 and 3 in that only a single bottom member 83 is disposed on the base l, in that the lower and upper blade'holding jigs,

the filler blocks, the blades, and the filler block clamping members are omitted since the core to be formed therein is to be devoid of elements, such as blades, extending transversely therethrough, in that no cross member I8 is present, and in that the top portions of the drag members 2 and 3 are provided with outwardly extending flanges 84 and 86 adapted to be engaged on their undersides by rollers carried by the modified form,

of core :blowing head-8l disposed thereon.

Head 81 comprises'a first member 88 having a depending flange 89 provided with rollers 9| adapted to engage the underside of the flange 86 ondrag member 3 and having its opposite end bifurcated so as to provide in effect an elongated slot 92, and a second member 93 having an intermediate flange 94 extending downward between the bifurcations of the first member and carrying a'roller 96 adapted to engage the underside ofrtheflange 84 on drag member 2. The second member is also provided with a pair of elongated slots 91 which overlie the bifurcations of the first member and a pair of cap screws 98 extend through each slot 91 and into the underlying bifurcation of the first member for securely clamping said first and second members together as a ;The second member. carries a nozzle 38.

which extends .through the slot 92'and into the core'box andis also provided with an additional nozzle receiving. opening 99 which is closed by the plug IDI. When the head is to be applied to a wider core box, the cap! screws 98 are loosened and the first and second members moved until the rollers carried by the flanges 89 and 94 engage the underside of the flanges on the drag members corresponding to the flanges 84 and 88 on the drag members 2 and 3 shown in Figs. 7 and 8. If the width of the box is suflicient to bring the plugged nozzle opening 99 in alinement with the slot 9.2 in the first member, the plug can be removed and a second nozzle inserted therein. The first and second members are each provided with upwardly projecting handles I02 and I93, respectively, to. facilitate moving the head along the core box to progressively blow same. Nozzle 38 is provided with a sand confining member 14 which has a width only slightly less than that of the core box and which has one end extending downward beyond the discharge end of the nozzle 38 and to a point adjacent the bottom of the box as is clearly shown in Fig. 9. A relative movement of the head and box so as to produce in effect a movement of the head along the box in thedirection indicated by the arrow in Fig. 9, results in the formation of a progressively moving compartment into which the discharge end of' the nozzle projects. When a Wider boxis used, a wider sand confining member must be used and a similar modification is required with respect'to the head structure shown in Figs. 1-4;

inclusive. In addition, if two nozzles are employed, the sand confining member must be provided with openings for the passage of both noz- Zles therethrough or separate confining members may be employed as taught by the construction shown in Figs. 1-4, inclusive.

Whether the sand confining member or members are carried by the nozzles 38 or are carried by some other portion of the head is entirely immaterial in so far as this invention is concerned as is also the particular shape and the construction of such members. All thatis necessary in this respect is to employ a sand confining member or members arranged to coact with the interior of the core box and with any elements which may be disposed therein to form a compartment intowhich the nozzle or nozzles project and which may be progressively moved throughout the length of the box by effecting a relative movement of the box and head. Inthis connection, it is entirely immaterial whether such relative movement is effected by moving either the box or head or both, but it is usually more practical to move the head relative to the box than it is to move the box relative to the head I or to move both the box and head. The invention relatively long and narrow cor forming portion,

'a relatively short core blowing head disposed on said box so as to transversely bridge said core forming portion, said box and head having eoacting retaining parts rendering. said box and head relatively movable;- for producing: in eifect a movement of said headalongi the comiormingi portion of said box,. a source of sand, means: op.- eratively connecting said sourcewithusaid head,v and means operative. to cause sand toi pass: from: said source through saidtconnectin'g' means and through said head.

2. In combinationv with a core box having a: relatively long and. narrow core forming: portion, a relatively short: core blowing head movably mounted. on said box so as to. transversely bridge: said core forming; portion, said head being mov-- able along the core. formingportion; oi said box;

a source of sand, means. operatively connecting said source of sand with said. head, and means operative-to cause sand to pass from said source through said connecting'means. and through said? head. i

3. In combinationwith a core box having a relatively long and narrow core forming portion in which is disposed a series of. longitudinally spaced and transversely extending elements, a. relatively short coreblowing head transversely bridging the core forming portion. of said box, said head having a" nozzle andsand retaining,

portion which extends into thecore forming portion of said boxand. which formsiwith the proximate transverse edges of a plurality of said elements a substantially closed comp-artmentinto which the nozzle projects, said box and head being relatively movable for producing in effect: a movement of said head along the core forming.

portion of said boxto therebycausesaidinozzle and retaining portion to successively coact with the proximate transverse edges of the remaining;

elements and formtherewith compartmentsinto.

which the nozzle successively projects, ,a source of sand, and means operative to causesand to pass from said source through said connecting meansand. through said nozzle. 4. In. combination with a core box having a relatively longand narrow core forming portion.

in-whichis. disposed a series of longitudinallyspaced. and transversely extending elements and an elongated clampingmember spaced fromthe sidesof' said box and engaging intermediate. por

tionsof the proximate transverse edges on said elements, a relatively short core blowing head transversely bridging the core forming portion of said box, said headhaving a pair of spacednozzle andsand retaining. portions which extend. into the spaces provided between the sides of said clamping member and the opposed sidestof. said box and whichform with the exposedportions of the.proximatetransverse edges of a plurality of elements a. substantially closed. com-- partment. into which the nozzles project, said box and head being relatively movable for pro-- ducing in effect a. movement of said head along the core forming portion of the boxto thereby cause said pair of nozzle and sand retaining portions to successivelyv coact with-the. exposed portions of the proximate. transverse edges of the: remaining elements and form therewithcompartments into which the nozzles successively project, a source of sand, means operatively connecting saidsource of sand with said pair of. nozzle and sand retaining portions, and means operative to cause sand to pass from said source through said connecting means. and through the said nozzles.

5. In combinationwith. a core box having a relatively long and narrow arcuate shapedcore forming portion, a relatively short arcuate shaped acesgms of said box, a source of sand, means operatively connecting said source of sand with said head, and means operative to cause sand to pass from saidvsourcethrough said connecting means and through said head.

6-; A portable core blowing head adapted to be attached to an elongated core box in a manner transversely brid'ging'same and then moved along the-core box to progressively blow sand thereinto comprising a head plate having a projecting part adapted to movably engage a retaining part on a core box, a blowing nozzle extending through said head and into the core box, and a sand confining member operatively associated with the discharge end of saidnozzle and including an end portion arranged to extend'into the core box beyondthe disoharge end of said nozzle.

7 A portable core blowing head'adapted to be 1 attached to elongated core boxes of different width in a; manner transversely bridging same and then moved along the core box to progressively blow sand thereinto comprising a plurality of members forming a headplate, saidmembers beingadjustably connected soas to render said head plate applicable tocore boxes of different Width, one of said members having an elongated opening therein which isv arranged to extend transversely with respect to the. longitudinalaxis oi the core box on whichthe head plate is to be operatively positioned, and a nozzlesecured in: and extending through another one-oi said members' and also through the elongated: opening in the said one member.

8; A portable core blowing head adapted to be attached to elongated core boxes of different width in a manner transversely bridging same and thenmoved alongthe core box to progressively blow sand thereinto comprising a plurality of members forming a head plate, said members" being adjustably connected so as to render. said head plate applicable to core boxes of different width, one of said members having an elongated opening. therein which is arranged to extend transversely with respect to the longitudinal axis of the core box on which the head plate is to be operatively positioned, a nozzle secured in and extending, through another one of said member having a. projecting part adapted tomovably engage a retaining part on a core box, said first member also havingan elongated opening therein which is arranged to extend transversely with respect to the longitudinal axis of the core box, and asecond member overlying said first" member and having. a blowing nozzle projectingthrough the elongated'opening in said firstmember, saidfirsta'nd second members being adjustably connected so as to form ahead plate applicable to core boxes ofdifierentwidth bottom and-side wall portions of an elongated core box a sand receiving and confining compartment movable longitudinally of the core box to progressively blow sand thereintovcomprising a head plate positionable to cover, a predetermined length of such a core box in a manner rendering said head plate and core box relatively movable longitudinally, a sand confining member carried by said head plate in depending relation adapted for disposition between the side walls of the box to form with said head plate and with the contiguous side wall portions'o-f the core box a sand confining compartment, and means for blowing sand through said head plate and into the compartment defined in part by said head plate and member.

11. In combination with a bore box having a relatively long and narrow core forming portion, a relatively short coreblowing head positioned to cover a'predetermined partial length of said core forming portion in a, manner rendering said box and head relatively movable for producing in effect a movement of said head along the core forming portion of said box, a sand confining member carried by said head in dependto form with said head and with the contiguous side wall portions of said box a sand confining compartment, a source of sand, means operatively connecting said source with said head, and means operative to cause sand to pass through said connecting means and through said head into said compartment.

' 12. In combination with a core box having a relatively long and narrow core forming portion, a relatively short core blowing head positioned to cover a predetermined partial length of said core forming portion, means retaining said box and head in operative relatively movable relation for producing in effect a movement of said head along the core forming portion of said box,-

a sand confining membercarried by said head in depending relation between the side walls of the box to form with said head and with the contiguous portions of said side walls a sand confining compartment, a source of sand, means operatively connecting said source with said head, and means operative to cause sand to pass from ing relation between the side walls of said box 

